【摘要】 在pH值为 11 4的二乙基二硫代氨基甲酸钠 (DDTC)体系中 ,采用循环伏安电位扫描、恒电位阶跃和计时电位法研究了黄铁矿的电极过程。循环伏安曲线表明 ,当c(DDTC) =1× 10 - 4 mol L时 ,电极电位大于0 2V(SHE)以后 ,黄铁矿电极表面发生四乙基二硫化秋兰姆 (TETD或D2 )的电化学沉积并残留在电极表面 ;采用恒电位阶跃法可以确定反应电流密度 (i)与反应时间 (t)之间的关系式为i =(9 0 8× 10 - 5 + 4 77×10 - 3 t0 5 ) - 1 ,由此可以确定DDTC在黄铁矿电极表面的扩散系数D为 3 72× 10 - 6 cm2 s ,TETD在黄铁矿电极表面的吸附厚度可达 1 6 3个单分子层 ;计时电位法则确定了pH为 11 4时 ,吸附于黄铁矿电极表面的TETD的电化学动力学方程为 η =0 116 -0 0 6 4lg[1-(t τ) 0 5 ] ,电化学动力学参数确定为 :交换电流密度i0 =3 0 8μA cm2 ,反应电子数n =2 ,反应传递系数α =0 46 2。电化学动力学方程和电化学动力学参数值表明吸附于黄铁矿电极表面的TETD易于还原更多还原

【Abstract】 The electrochemical process of pyrite electrode in diethyldithiocarbamate (DDTC) solution with a pH value of 11.4 has been investigated using cyclic voltammetry, Potentiostatic method and Chronopotentiometry. At 1×10 -4 mol/L of DDTC the electrodepotential is higher than 0.2 V, resulting in electrochemical deposition of tetraethyl thioram disulphide (TETD) on pyrite surface. The dependence of current density ( i ) on reaction time ( t ) is established using potentiostatic method as follows: i =(9 08×10 -5 +4.77×10 -3 t 0.5 ) -1 . From this the diffusion coefficient, D of DDTC on pyrite surface in the DDTC solution is ascertained as about 3 72×10 -6 cm 2/s, and the thickness of TETD adsorbed on pyrite surface is about 1 63 molecule layers. The electrochemical dynamic equation of adsorption of TETD on pyrite surface at pH 11 4 is established as η =0 116-0 064 lg[1-( t/τ ) 0.5 ] and the electrochemical kinetic parameters are determined as follows: exchange current density, i 0=3.08 μA/cm 2;reaction electron number, n =2 and transmission coefficient, α =0 462.更多还原